Has anyone had an occasional problem with playback on their Apple TV 4K. A couple times a week, when I try to play something in Channels, the screen just looks like snow. I can back out of it, try again and it works fine. I THINK it's on both recorded and live tv but I didn't think to track it until now. I suspect it's a problem with the Apple TV itself. I have two identical boxes and I have never seen that problem with the other. Updates haven't fixed it. I haven't seen this with any other apps, but I rarely use any others on that box.
I've had the same symptoms once ("snowy" picture) and it turned out to be a faulty HDMI cable.
This may not be your problem but this is easy to check: swap HDMI cables with your other box. 
Ahh... Thank you. That's a good thought. I'll give it a shot.
Just following up. Any luck?
I have been traveling so I haven’t had a chance to test it much. I’m finally returning tonight so I give it a week or two to test. It doesn’t happen all the time but it’s frequent enough.